Dimethylformamide → 3-(1-phenylsulfonyl-4-hex-1-ynyl-1H-pyrazol-3-yl)-pyridine

Participants

Reaction Conditions

Reaction Steps

To triethyl amine (10 ml) and DMF (4 ml) containing 36B (0.97 g, 2.36 mmol), was added 3 eq of hex-1-yne (0.81 ml). The resulting mixture was stirred for another 2 hours under N2. Successively were added 10 mol % of CuI (45 mg), 5 mol % of PdCl2(PPH3)2 (83 mg) and 18 mol % of PPH3 (111 mg). After the addition, the resulting solution was warmed at 70° C. for 18 hours under N2. After cooling to room temperature, the mixture was diluted with ethyl acetate, washed three times with a saturated NaHCO3 solution, dried (Na2SO4), filtered and concentrated. The resulting residue was purified by flash chromatography (diethyl ether/PE (1/1)) to afford 3-(1-phenylsulfonyl-4-hex-1-ynyl-1H-pyrazol-3-yl)-pyridine (43A) as an oil (0.66 g, 77%). 1H-NMR (400 MHz, CDCl3): δ 9.5-9.2 (bs, 1H), 8.8-8.4 (bs, 1H), 8.34 (bd, J=8 Hz, 1H), 8.21 (s, 1H), 8.08-8.04 (m, 2H), 7.67 (bt, J=7 Hz, 1H), 7.57 (bt, J=7 Hz, 2H), 7.41-7.32 (bs, 1H), 2.42 (t, J=7 Hz, 2H), 1.62-1.53 (m, 2H), 1.49-1.39 (m, 2H), 0.93 (t, J=7 Hz, 3H).

Provenance & Evidence